The present invention relates to a disk recording and reproduction apparatus for recording and reproducing information to and from a disk used as a recording medium. More particularly, it relates to a dynamic damper for damping vibration in a disk recording and reproduction apparatus which positions its head by linearly moving the head in the radial direction of the disk.
As having been disclosed in Japanese Laid-open Patent Application, Publication No. Hei 2-292781 for the invention of "A voice-coil type optical head" for example, a conventional disk recording and reproduction apparatus comprises a disk drive mechanism for supporting and rotating a disk used as a recording medium, an optical head for writing and reading information to and from the disk, and a positioning mechanism for positioning the optical head. The conventional disk recording and reproduction apparatus having been configured as described above is provided with a dynamic damper having a function to damp vibration in a specific direction so that the optical head can be accurately positioned at a target track on the disk.
The dynamic damper of the conventional disk recording and reproduction apparatus disclosed in Japanese Laid-open Patent Application, Publication No. Hei 2-292781 comprises a weight having a large mass and an elastic element. The weight is bonded to the elastic element which is fixed to a member whose vibration is to be damped. By using the dynamic damper being configured described above, the conventional disk recording and reproduction apparatus damp vibration from the drive mechanism to some extent, to improve the positioning accuracy of the optical head.
Generally speaking, with an increase in the mass of a dynamic damper, a frequency range of vibration to be damped becomes wide. However, it is very difficult to bond a weight having a large mass to an elastic element having a viscosity, in particular, a gel material. For this reason, the frequency range of vibration to be damped cannot be made wider, thereby causing a problem in product reliability.
In addition, in the above-mentioned conventional configuration, it is necessary to install a dynamic damper in each direction of vibration to be damped, thereby causing a problem of making the apparatus larger and heavier.